const fs = require('fs');
let promise = new Promise((resolve, reject)=>{
    fs.readFile('./100.txt','utf8',(err,result)=>{
            if(err != null) {
                reject(err)
            }else {
                resolve(result)
            }
        })
});
promise.then((result)=>{
    console.log(result)
}).catch((err)=>{
    console.log(err)
})